Fluid-pressure governing system



Feb. 24, 193 1. A. F. SCHWENDNER ET AL 1,793,514

FLUID PRESSURE GOVERNING SYSTEM Original Filed Sept. 8, 1924 5 sheets -sheet 1 WITNESS ATTORNEY Feb? 1931- A. F. SCHWENDNER ET AL 1,793,514

FLUID PRESSURE GOVERNING SYSTEM Original Filed p 8; 1924 5 Sheets-Sheet 2 Ewen-(ions z A-F; fichwcnder I d, J: Myers ,ID ecfcL WITNESS Q1 MXe EXGc.

ATTORNEY Feb. 24, 1931.

A. F. S CHWENDNER ET AL FLUID PRESSURE GOVERNING SYSTEM Original Filed Sept. 8, 1924' 5 Sheets-Sheet 3 fnperofiar-s A F Schwendel.

fags. I

and. MyersJDcH b QL,M ers.Ex -c.

' BY ATTORNEY WITNESS Feb. 24, 1931. A. F. SCHWENDNER ET AL 1,793,514

A FLUID PRESSURE GOVERNING SYSTEM Original Filed pt- 8, 1924 5 Sheets-Sheet 4 Imuerulrcrs F 'A- E Schwe'ndcm,

WlTNESS 9' n J- S. Myer-sjDecd.

6 by MyersfE xec. I D I Q BY M ATTORNEY Fe 1931- A. F. SCHWENDNER ET AL 1,793,514

FLUID PRESSURE GOVERNING SYSTEM 5 Sheets-Sheet 5 Original Filed Sept. 8, 1924 v P. 2. on w a C 5 my 1 A w V/JM I mil/l IIIII// 1 Q A 4 1 A A m G l-ll I ML J5. Myersf l).L.Myers,'Exec.

WITNESS MAM ATTORNEY Patented Feb. 1931 UNITED STA TBS.

{ANV'TQEIONY F. .SGHWENDNER, or nssI-N'G'ToN, A nJonNas; MYERS, nnonnsnn, LATE or rmnannnrnm, PENNSYLVANIA, BY GRACE L; MYERS,"EXEC'UTRIXQOE PHILiA- DELPHIA, PENNSYLVANIA, ASSIGNOR S TQ-"WESTINGHOUSE ELEGTRIC &'MANU- FACTUR-ING COMPANY, ACORPORATIONIOF PENNSYLVANIA;

' rLUrn-rREssUBE eovnnivr vor'svsr EM- 'Origiixal application filed September 8,

ing systems, more particularly to governing Systems wherein"variable fiuid pressure is used to control or actuate admission valvesor other, parts, and it has for its object to provide apparatus of the character designated which shall operate efiectively and reliably,

' and which shall provide adequate variation in fluid pressure for operation of the valves upon change in'the speed or other-operating condition of the. apparatusto be governed. Another object 1sto.prov1cle a governlng system which is particularly suitable where the admission valve or other apparatus to be controlled is at a remote distance from the speed @responsive orequivalent control ele;

:inent. 1 u p "The invention has :for' another .Qb eCt tov provide a governing system for a prime mover which embodies a hydraulic actuating system which shall be extremely sensitive to the changes in the speed of the prime mover and which shall be capable of operating successively a plurality, or. series of admission valves in any desired sequence and in any desired overlapping relation. 1

. The operation of motivefiuid admission valves by hydraulic pressure systems has .been generally recognized as providing a. very eliectiveimethod for controlling the speed 01": a prime mover. Such systemsjgenerally comprise a pump of the. dynamic typewhich develops pressure in accordance with the scale of the speed anda pressure-responsive device for actuating the admission valve.

-The simplest form of pressure-responsive device is an abutment or pistonsubjeet to fluid pressure upon one side and to spring pressure uponthe other side.- However, with high ,fiuid pressures, the spring becomes 1nordinately long andiimpractical, in order that suflicient pressures may .be sustained and, at the same time, a suflicient rangeofmovement permitted to permit of extreme sensitivity. Accordingly, itiisthe object ofthe present inventionto provide apparatus which will give the requisite initial .holdingpressure and,

736,660pfiled September 8,.

'nism or other devices requiring a widely varylng fiuld pressure;

lbs. per square inch overa. base pressure of 1324,; Serial $10,736,660. hivided and this "application filed Oetober 7, war -seri l no. 224,631.; 1

the same time,-be extremely sensitive to very I slight fluctuations from that pressure.

,The present invention embodies a :de'vice for transforming fluid pressure having only slight variations, to a second fluid pressure by-any suitable former-pressure transformer :55 hav ng wide variations. Thlsisaccomplished;

device,' for example, by means-of "a valve member adapted toadmi't fiuidfroma source or fluid pressure to a pressure -chamber or to exhaust fluid therefrom." Pressure-raped s'ive 'ine'an's are arranged'in communication with the pressure'chamben'said means being adapted to'int'errupt thefiow of fluid to. or

from said chamber .upon'd'efin'ite movement f thereof, Whatever the position of the valve member. The valve member may be actu ated by any suitable means from. an outside source, several of which are"*illustrated and deseribefd in this specifieationf The pressure within the pressure chamber there-fore varies with the pos tion vof the valve'jmember and may be utilized to operate governing mecha-f it particular embodiment of the invention comprises a pressure transforming device having a piston which'is held against the initial fluid.pressuregenerated in operation by a load spring. This piston is so arranged that small movements thereof-are sufiicient for permitting the hydraulic liquid to act upon a "secondary piston controlled by a spring having a greater scale which permits of very sulostantial pressure changes for slight movements oi 'the p ston. In this manner, the variations'in pressure are multiplied,

that is, should the prime mover acquirega speed eiiective to. produce an increase of 2 20lbs. ,the latter pressure beingproportional to the orthe amount of encess pressure me i 2 f' 1,793,514 v a acting upon the primary piston. The oil at sure derived from the transformer device.-

the 20 lbs. pressure isdischarged from the pressure transformer device and is conveyed to any well-known form of pressure-respom sive deviceor, for larger units, toa'novel form of motor for actuating the admission valve. This motor is SQfCODStIUClZGd that-its movements are controlled by a spring which is sub ect to the widely fluctuat ng fluid pressures generated in the transformer de-.

vice. An extraneous liquid having substantlal pressure and responsive to the pres is employed as motive fluid for moving the admission valve in either direction. In this manner, the movements .of the admission valve are positively controlled at all times and, when the admission valve'is in a closed position, t is held upon its seat with such a preponderance of pressure as will avoid any possibility, of leakage.

The employment of hydraulic transmission system, such as ab'ovedescribed. for 0011- trolling the admiss on of motive fluid to a prime moverin response to the speed there? of, is to be preferred over'tliefrequently employed mechanical ineans inasmuch as the hydraulic system permits greater'latitude in positioning the various elements with re 'spect to each other. Furthermore, the hydraulic system of controlling is especially adapted forusewith prime movers having a plurality of admission valves-whichit is do sired to operate in sequence; 1

The above and other objecawhiehiwill following specification and illustrated in the accompanying drawings, in which Fig. 2 is a sectional elevation of the valve motor employed in F 1:

Fig. 3 is a sectional elevation of" the pressuretransformer employed in Fig. 1

I Fig. 4 is a diagrammatic angement ot a prime mover having its'motiv'e fluid adnns sion' valves actuated another form of the livdraulic transmission system;

Fig. 5 is a sectional elevation of the valve and pressure-responsive device employed in Fig.4; Fig. 6 is a sectional elevation of another embodiment of the pressure transformer which is suitable for mechanical actuations as by a centrifugal governor; i

Fig. 7 is a sectional elevation of still another form of the hydraulic transmission system; and

Fig. 8 is a diagrammatic arrangement of a term of governing system, in which the pres sure transformer illustrated in Fig. 6 may be employed. p 7

Referrmgto the drawings for a more detailed description of thenivention, there is shown in Fig. 1 a prime mover 10, such as a steam turbine, provided with primary, secondary and .tertlary motive fluld admission "valves 11,. 12 and 13,;respectively. These tion. The valve motor 18 has a bodyportion 19. which is rigidlyisecured to'the valve body 14:. Disposed within the bore of the body portion 19 is a plunger 21 provided with a cylindrical interior 22 "and an" actuating piston23i' Actuating fluidinlet ports 24 and '25, ,which communicate, respectively, with oppesite'sides oi the actuating'piston 23,'a-re provided in the plunger. Interposed be tween the inlet ports are'discharge ports 26 which communicate, through a circular recess 27, with a connection 28 provided in thebody portion19 forthe discharge of the actuating fluid. I

Arranged within the hollow portion 22 of the plunger 21 is a hollow piston valve 31 for controlling the admission of actuating fluid to the'opposlte 'sid'es'ot' the piston 23.

The valve 31i-s provided at one end-wih a Y fluid-tight'plug 32. Fixed rse cured con,- 7 y I 1 centrically within the piston valve 31 -is a be made apparent throughout the further-dc} scriptionof the inventiomare set forth in the sleeve member 33 for conveying actuating fluid from an inlet port 3% provided in the body 19, through openings in 'the plunger 21 and the piston valve 31,to ports 35 and provided'in thepistjo'n'valve 31. The latter ports distribute the fluid. to the opposite sides of the piston 23, by cooperation with he ports2-l and 25... An exhaust port 37 formed by an annular recess is provided in the piston valve 31 for placing the respective ports 2% and 25 in communication with the dischargeconnection 2S. 2

Located in the body portion'.19'o'l"the valve motor is an inlet 38 for permitting governing fluid to act upon the transverse face or the piston valve31. An equalizingconnection 39, which communicates through a conduit tlavith the governing fluid" inlet 88, and a leak-off connectionfl2 are provided in the lower portion of the motor body for maintaining a balance ofpressures between the oppositely-disposed transverse faces of the plunger 21. Movements of the piston valve 31 are controlled by a spring 44 which is maintained under an initial tension between the body portion 19 of the valve motor and the remotely-disposed end of the piston valve 31. The pressure of the liquid required to actuate the valve may, if desired, be altered by means of an adjusting-screw 4:6. Vihile the motor 18 has been'described-as actuating an admissionvalve,1t is to be understoodthat' its use is not confined solely thereto and that it maybe employed for imparting a.-re-. ciproca'lory Th-emotive fluid admission valves 11;- 12 and'13 are supplied with steam; as shown in Fig. 1 by a common conduit 5lzprovided with branch conduits 52' which communiand a pump 57 for generating The governor pump may be designed to maintaln a hydraulic pressure of, for example, 60- lbs. per square inch when the prime mover 1s operating vat'its desigz ned speed. while the pump 57 may be designed to generate a 1 nnnim'um-pressure of 60 lbs. when the turbine is operating at its lowest speed, The

pumps 56 and 57 discharge hydraulic fluid to a pressure transformer device .59, I

As shown .in Fig. 3, the pressure transformer device comprises a body portion 61 having disposed therein cup-shaped inner and outer concentric piston valves 62 and 63 The outerpis'ton valve 63 isprovided with inlet and discharge ports 64 and 65Wl110h communicate respectively with anfactuating fluid inlet connectionfiti and a dischargecon nection 67. The lower transverse face of the outer piston valve 63 is disposed 1n a chamvalve 63 arecontrolled by a load spring 7 6 which exerts a pressure sufficient to balance the hydraulic pressureacting upon the oppositely-disposed end of the piston valve. As

this spring must withstand the base load generated by the governor pump. the scale is necessarily such as to permit of only limited movements of the outer piston valve 63 for slight fluctuationsin pressure acting on the relatively small annular area of the lower end of the valve. The thrust of'the hydraulic liquid acting upon the piston valve and the thrust exerted by the spring 7 6 may be equalized by adjustments of the screw 77. The

inner piston valve 62 is provided with inlet ports 78 and outlet ports 7 9 which cooperate with the ports 64 and 65 provided in the outer piston valve to control the supply of:

hydraulic fluid to and the discharge of hydraulic fluid from the interior of the inner piston valve. The movements of the inner piston valve 62 are controlled :by a spring 81 so proportioned that a predetermined pressure ofliquid for any particular location of V the piston is obtained. A speed changer 82.

isprovided for altering the setting of the spring 81. -The pressure formulated withln the inner piston valve 62 is conveyed through movement to innumerable forms 'o-i' apparatus.

to the actuating fluid inlet-ports '38 provided in the valve conduity68" connects the discharge of the r actuating fluid pump 57v with thei inlet connection' 366 of the 7 pressure: transformer :device lwhi'le .a. conduit 69 is provided for. returning thefiuid toithe pump. The conduit 6-8 is provided with :a branch 70 which connects with :t he--in-let port 34 of the respective, valve motors for supplying fluid for actu-- sting the valves while branch .conduits7landn main conduit- 71' are provided for returning the actuating-fluid from. the valve motors to the pump suction, the branch conduits 71.

communicating with the .dischargeconnections 28. The variable pressure of the liquid generated by the governorlpumprfifi istransmitted by: a conduit: 7 3 .whichfconnects vwith the connection? 2 of the i-pressuretransformer device. The-pressure formulated within the. I i

transformer devicefisconveyed by a conduitmotors 18lofqthe"respective;admission valves 2 7 1 1; l2and 13."

84120 the governing-fiuid-inlet connections 38 1 protsridedin therespective valve motors. j

The operation of the above embodiment of hample,..60 lbs. per squareiinch, the variationsv 1n speed of the prnne mover efiecti-ng anincreaseror:decreasefrom that pressure-for governingzpurposes. (As it is. frequently-flet b ein :pxrime movers of the 'high speed, her 68 provided with a governing :fiuld con-f -nection 72. Themovementsof the plston 'the'invention is as follows: The rotations of speed within; 3 per cent. and :as the resultantv fluidpressure changes thus produced would b ionly 6 per cent, it may be readily appre cia ted that the fluctuations :in the pressure of the governing'fiuid are rather. limited. The

pump 57 generates-fluid pressurefor actuat ting the valvemotors 11. 12 and .13, the presconnection -66 provided in the pressure transformer device 59".and through a conduit 70 fluid inlet ports 34 of the respective valve motors. Within the latter. the actuating fluid is confined within the annular chamber intervening between the sleeve member 33 and the piston valve31.- The'variations in pressure generatedby the pump 56, whichvariations are in response to the speed "ofthe prime mover, are conveyed by the conduit fluid inlet connection former. Within the 72 of the pressure transtransformer, thev govse: i

r type to confine the fluctuations in running 7 3 to thegoverning erning pressure-acts upon'the annular lower:

transverse face 'of-the outer piston valve 63 I and overcomes the. force-exerted by the "load spring 7 6. As the l'oadsprin g 16 must :nec-' pressure generated by the pump, lbs. per square inch, any variation:

inthel'housing. V

- Shouldthis be an increase 1n pressure, the inlet port .(l l'is moved into Communication with the inlet port 78ito permit the actuating fluid to enter the interioroflthe piston valve trolled by the (i2 and flow through the outlet 83 and conduit 8 1- to the governing fluid inlets 38 provided in" the 7 several] valve motors. The amount of pressure created therein is conspring 81, which 7 s of relatively greater scale, and which permits the accumul'ation of a predetermined pressure of liq uid for anysettingof the outer pistonvalve. Upon. accumulation or" :the latter pressure, which may, if desired, be 20 lbs. per square inch, the relative movement of the ports 78 of the inner piston valve-and the ports 6& of the outer piston valve 63 cuts off the-admission offurther fluid. I

20 lbs. per square inch'thus The pressure of.

the transverse area of the formed acts upon piston valve and upon overcoming the force of the spring l l, moves the valve to permit the actuating fluidjwhich is present in the.distributingports 35 to pass through-the inlet ports 2a and act upon the upperfaceof the actuating piston s3, causing a downward movement of the piston 23 and consequently restricting the How ofmotive steam through the valves.l1,f12 and 13..

' the {port 87 comes into communication with the p'ortsi25, perniitting the-fluid beneath the" actuating piston'23 to be discharged through the discharge ports 26 and the communicating conduits to the inletot-the pumps.

Any decrease in the pressure of the fluid generated by the I governor pump 56 permits a lowering of the'outer i'stonvalve' 63 and discharge connection (37 fore, only a fluctuation sleeve 62 to close the ports 67.

a return of a portion of the fiuid through the and conduit 69 to tl inlet of the )uinps, until the pressure within the sleeve 62 has been reduced sufficiently to permit the spring 871 "to move the The reduced pressure acting upon the piston valve 31 of the inotor permits the actuating liquid to move the piston 23 upwardly, thereby admitting additional motive fluid to the prime mover. The actuating fluid, which has been present onthe upper face of exhausted through the ports 35 and '8'? and the discharge connection 28 to the conduits 71 and 71 for returning the same to the inlet- While there may be, thereof thepumps.

of from to 61 or (32 lbs. in the pressure generated by the govnevertheless, the transformer ing pressures of possibly IQ to 20 or 50 lbs, thereby increasing the difierential pressure At the same timep -sition'of:tl1e. -valve 63. a?

the piston 23, is.

thelsprings 4A inthe respective motors with such relatively-different initial loadings that,

the opening of each successive valve-precedes the closlng or" the prior valve, thus obtannng a non-lnterruptcd and continuous flow of mo-- tive fluid toithe prime mover. The respective sprmgs may be accurately ad ustcd by means of the screws 46.

Referring tothe pressure transformer 59;

it will benoted that thisdevice provides a and producing very sensitive :and accurate.

pressurewnich isa function ofthe position 7 ofthe' outerpiston valve 63.

valvei62iassumes a position corresponding to; that of the valve 63'. Hence, thepressure within the valve 62' is 'af functionof the po- I hepressure within 7 the nterior. of the, inner piston valve lVhile thei'motive fluid admission valves 11, 12 and 13 have been illus trated being operatedbya novel lorm off-fluid 'lOi-Ql' de--- vice, it is to .behnderstood that there may be employedany wellknown form of pressureresponsive device for actuating the valves. Furthermore, there maybe employed only one pump, which pump shall generate fluid pressure, for both governing-and actuat ng purposes. 7 w v p i As shown in Fig. l, the primeimno it) is provided with" a governor pump and a pressure transformer device 59 which may he of the type illustrated in Fig. 3. v The prime mover 10 is provided with the jnimarv sec-- onda'ry and tertiary motive fluid adi sion valves 11, 12and; 13in the usualn .mner. The governor pump -1lO may bedesigned to generatega pressure of ('30 pounds when the turbine is operating at its lowest speed, any increasein speed resulting in the generation of a higher pressure. Fluid pressure dis charged by the pump is conveyed by'means ofa conduit 11 1 to the actuatingtiuid inlet connection 66 and thegoverning fluid connection 72 of the pressure transformer device. The pressure transformer device multiplies the relatively small "fluctuations.

site; face. of the piston. A'

connection 119 is provided. V

lVith the above arrangement, the widely i sure generated by p mp in response/rte changes-.inrstpee-de Ofith primemover in a mannerheretofore"described. The transformed; or Widely fluetur between the-"opposite face of the piston 115 and an abutment 1:17. is a springl l8'for op posing pressure of fluid actingupoiithe oppo-' fluctuating fluid pressures generated in the I transformer device 59- actdirectly upon the pistons 115 ofthe pressures-responsive mechanisms to control; the: admission-of motive fluid to the prime mover. Fluid @is returned from. the transformer device 59 to the inlet of the governor pump 1 10- by a conduit 121.

suffieient to act as motive fluid. for moving the admission valves. I

In Fig. 6. is shown anembodimentof a. pressure control device, similar to the; pres,

sure transformer device,v which, may be op- I ei'ated mechanically as by a'centrifugali governor; I I'HthiS embodiment; the outer piston I valve, instead ofbeing actuated by-fluid pressure, is moved mechanically-througha lever I. VI 181 by a centrifugal governor 182 in'response I to the speed of the prime mover. Hydraulic fluid leak-oil connections 183 andl-SLare provided for permitting the outer pistonto move freely Within the transformerbodyv ,MOVe

nients'of :theoutfer piston valve control. the admission.- andi-discharge offihydraulic fluid to the inner piston valve, which acts in a manner heretofore described to control the I valve motors.

The hydraulic transmission system is .therefore adapted for connecting the wellknown form of mechanical governor tothe motive fluid admission valve. n lieu of the usual lever system, very small movementsof the governor effecting substantial changes. in

the. pressure of the hydraulic-fluidcontrolling the movements of the admission valves An arrangement such a this isvery desirable in installations wherecthe governor and theadmissionvalve are arranged at a substantial distance apart from each other or, Where a plurality of admission valves must be controlled. The mechanically operated pressure control device illi'istrated in Fig. 6 may tial increases in fluid suitable leak H mi-ssion valves.v ,7 v w I A 'sillustrattlve in Fig.1 tliere; is shown'a pressuretransformer'device 131,fwhi1c-li is gen- I I 'An arrangement such as-above describedis- 'especially'adapted foruse with. prime movers of smaller capacities, inwhich the fluid presthe governing pump is the outer piston valve controlling the movements of primemovers.

in the d iflierent arrangements. of hydraulictraiismission systems heretofore described, there is. employ'eda fOflIlk'Qffiu-id pressure transformer device which produces substai 51475 I pressure for, slight i-n- '1 I creases pressure generated byt'he gov v ernor pumps. The 'd'evice,i however, may be readily adapted to ,Drov'ide az'secondfluid pressure varying inverse function of 'l the'flu-id' pressure generated by the governor" pump; that is, to eftectja substantialdecrease in pressure i n response to aslight inerease in pressure whichniaybe generated in the governing pump; 5 A veryadvantageous f a ture iof such an arrangement is vthat if the pressure of the governingflu'id -ishouldifail,-

:for any reason whatsoever, thepre'ssure-re- I 1 sponsive device closes the; motive fluidads erallysiniilar to. the transformer devices illustrated in FigsyB and 6,.v but which provides a second fluid functionof the fluid pressure controlling the pressure transformenf i 63 is extended: downwardly toprovide a; sleeve member l38 a'nd a weight portion 139, both integral therewith; 10o The casing '61. is also extended downwardly;

forming acylinder 13.7 in which the sleeve member 138S1ides I sleevemen ber is a spring; 141 which is connected at oneendtothe:Weight 1 39 and at 9 its opposite endtoan adjusting screw 142 which ispi'ovi-ded in the cylinder; Located in the lower portion of the cylinder is a connection 143 for admitting fluidpre'ssuregenv erated by the governor pressure enters, the cylinder 137. and ac-ts upon the transverse face of'the sleeve member 138 and the Weight portion 139, which-thus form F a pressure-responsive device for controlling theposition of the 'pist'onvalve 63. I lgvhilje as mentioned l1eretofor'e,fthis pressure may. fluctuate only one or two pounds the pressure-responsive device may tion thereof and the spring 141 may conse- 'quently be constructedbf "a relatively low- Any'increase in pressure results inanup-' I v ward movement ofthepiston valve 63 permitting the ports. 65 and 79 ,to cooperate to 'permit some of the actuating fluid to bereleasedthrough the discharge pipe 67 tode- V crease the pressure within'the interiorotthe pressure varying as an'inverse; .95 v f In this ein'bo'diiiient,

Arranged within: the,

"pump. This fluid 0 so designed a i that the Weight 1-39 substantially c nt r the base pressure generated by the; pump, 120 I that is 60 pounds. per square inch, or 'a-po r- I piston valve 62-. *Any decrease in governing fluid pressure results in z'r'downward mov ement of the pressure-responsive 1 device and .The pressure produced by the ed bya comhnt 1&8 to aform '=1DGCl12l1ll':il11 illustratedin Fig-7. It Will-bethe piston valve 63, and 7 8 to cooperate to admit additional actuating fluid to the interior of the inner p1s-' permitting the 'ports- 6 L ton valve 62 to increase the prcssure therein.

device is (tony o l motordei asillustrated, inaletail in Fig. 2, inodificdby inverting thesamc, or to the well-known form ofpressurc respousive noted that the latter is soarranged that upon failure otoil' pressure, a spr1ng1 l9 closes the admission valve, avery desirable-featurein numerous}installations.

In F1g%8,'1s shown another embodiment of the invention whereby agovernor may be adjnsted to control apparatus over a' Wide range ol speeds with substantially a constant- 01 low percentage of regulation. For exainplcaa 400 lb. spring-inightbe satisfactory for the.

manner that a single spring may be employed in the governor for effectively controlling the admission of motiveflluid at'a'll operating speeds;

As illustrated, a'centrifugal governor 90 is provided with a spring 91 and fluid-pressure means for opposing the centrifugalforceof the governing We ghts.

means may comprisea cylinder 93 anda piston 9% and'the amount'ot fluid pressure adinitted to or discharged from the cylinder 93 is controlled by a pressure transformer devlce 95, similar to that illustrated in Fig. 6. conduit 96 is provided for transmitting fluid pressure between the cylinder 93 and the pressure transformer device 95. With the above arrangement, the force'exerted by the spring 91 is supplemented with fluid at the necessary pressure." manually bya suitablelever mechanism.

The transformer device may be set The lever mechanism shown comprises a telescopically extensible lever'98 which issecured to a movable portion of 99, pivoted at 100, which is moved by a speedchanging lever 101.

transformer LlBVlCG.

With this system of control, a change in the setting of the-'speed-changing lever 101 eflects a displacement of the inner and'outer piston valves relative to the valve body, thereby changing the spring load and incidentally the pressure of thefimd which ismamtalned inthe cylinder 93.? However, it is notonly transformer 1 governor spring may fluid-pressure 4 system for the governor an d is pivoted, at its opposite end, to a bell-crank- "g'reater fluctuating fluid pressure, The lever 98 is secured, by a sliding connection, to a rod'102'f0r actuating the outer piston valve 63 of the pressure necessaryto produce, what maybe termed in sheet, achange in'the base load of the spring,

but it is also necessaryto changethe-scale 0t the spring.

7 Acoordingly, upon a movement of 'the'speedclianging leverlOl in either direction, the lever A 98' is displaced by the bellcrank 99 and the proportional lengths of the arms of the lever 98 are altered. As a result of this alteration, the extent ofthe movement imparted to the outer pistonvalve 63 by movement of thegovernonisincreased or decreased, thereby alteringtli'e pressure of the fiuida'cting upon the piston 94..- VVith'the "above arrangement',;a setting of thespeedchanging dev ce accomplishes both a change in the 1n1t1al or base pressure preva1l1ng within-the cylinder 93 and also effects suchalterafitions in fluid pressure asmay be accomplished A single by chan gin g the scale of the spring H a I therefore be employed to effectively govern the prime mover at-any number of deslred" speeds, thereby acc01nplishing similar results to those obtained with the-use of several springs having differentproportions While this invention has been shown in several forms, it willbe obvious'to those skilledin the artthat it is not. so limited, but is susceptible of various other changes and modifications, without departing from the spirit thereof, and it is desired, therefore, that only such limitations'shall be placed thereupon asare imposed by the prior'art, or'as are specifically set forth .in the appended claimsi e What isv claimed is: i s s 1." In a fluid-pressure operated governing a-prime mover having of motive fluid admission valves, nation 0t a'plurality of motor the combidevlces for regulating and actuating said admission 1 valves; a pressure transformer regulating the motor'devices, means for developing governing fluid pressure varying as a function of the speed of the prime mover for controlling the "pressure transformer, and -means providing for actuating fluid pi'essure for the motor devices. 4

-21 In a. fluid-pressure operated system, the

combination of means for developing govern- "ing fluid pressure, a pressuretransformer responsive to changes in the pressure of the governing fluid v for developing; a relatively a motor device responsive to the last-mentioned fluid pressure, and means for developing fluid pressure foractuating the motor device.

] i 8.; The combination with a prime mover having a motive fluid ad1nission"valve', ot

means responsive to the speed of the prime mover for sure, a pressure developing a governing fluid prestransformer responsive to changes in the pressureof the governing fluid for developing a widely varying fluid pressure, a motordevlce for the admission valve,

a plurality and means for developing the movements of said motor device being responsive to the last-mentioned fluid pressure, fluld pressure for cluding apressure transformer for provid ing a second fluid pressure varying as an inverse function of the first fluid pressure,

. the second fluid pressure being controlled solely by said pressure transformer, the lat- I applying said second fluid pressure to actu ter being responsive to the first-mentioned fluid pressure'and acting in response to the second fluid pressure to control the same, a valve for said prime mover, and means for ate said valve in an opening' direction.

- 5; In a governing systemfor a prime mover, the combmatronof means providing a fluid pressure varying as a direct'function of the speed of the prime mover, means providing a second fluid pressure responsive to.

and varying as an inverse function of the first fluid pressure,a valve for said prime mover, and means for actuating said valve in response to said second fluid pressure.

- 6. In a governing system for a prime mover, the combination of means'providing a fluid pressure varying as a direct function of the speed of the prime mover, means providing a second fluid pressure responsive to and varying as an inverse function of the first fluid pressure, a valve for said prime mover, and means'or actuating said valve in opening direction in response to increasein said second fluid pressure and in closing direction in response to decrease therein.

7. In a governing system for a prime mover. the combination of an impeller pump developing a fluid pressure varying With the speed of the prime mover, a pressure-transformer responsive to said fluid'pressure and providing asecond fluid pressure having greater variations than-the first fluid pressure, valves for said prime mover, a plurality of motor devicesf for actuating said valves, each motor device having-a pressureresponsive device, and means for adjusting each of said pressure-responsivc devices.

8. The combination defined in claim 7, and means i for adjusting the pressure transformer.

9. In a governing system for a prime mover, the combination of meansrdeveloping a fluid pressure varying as a function of the speed of the prime mover, means including a pressure transformer for providing a second fluid pressure varying in response to variations in the first-mentioned fluid pres sure, the second fluid pressure being controlled solely by said pressure transformer,

the latteribeing responsive to the first-mentioned fluid pressure and acting in response response to variations inthefirst-mentioned "fluid pressure, the second fluid pressure be ing controlled solely by said pressure transresponse to thesecond fluid pressure to conto the second ifluid pressure to control the 7 same, and a motor deviceresponsive to said second. fluid pressure.- P

10. I111 a' governmg system for a prime mover, the combinationofan'impeller pump 1 for developinga fluid pressure varying as a functionlofth e speed of the' prime mover,

means including a pressure transformer ,for' providing a second fluid'pressure vary ng; n

former, the latter being responsive to the first-mentioned fluid pressure and'acting in trol the same, and a motor device responsive to said second fluid pressure.

" 11. In a governing system for a prime "mover, the combination of an impeller pump for developing afluid pressure varying as a function of the'speed of the prime mover,

means providing a second fluid pressure varying in response'to variations in the first-- mentioned fluid pressure, thevaria'tions in 7 said second fluid pressure being-of greater magnitude than the variations in the firstmentioned fluid pressure, and a motor device responsive to said second fluid pressure. 12. In a governing system for a prime' mover, the combination of means develop ing a fluidpressure varying as a functionof the speed of the prime mover, means pro' vidinga second fluid pressure varying in response to variations in the first-mentioned fluid pressure, the ratio of operating range of variation to maximum pressure being greater in the second fluid, pressure than in the first-mentioned fluid pressure, and a motor deviceresponsive to said second. fluid pressure.

13. In a governing system for' aprime mover, the combination of means providing a fluid pressure varying as a. function of the speed of the prime mover, means providing a second fluid pressure vary ng in response to variations in the first-mentioned fluid pressure,the variations in said second fluid pressure bemg of greater magnitude thanthe variations in the first-mentioned fluid pres- I sure, and a motor device responsiveto said second fluid pressure.

In testimony whereof, We have hereunto 

